Heater.



HARRY s. DQIDD, 0F trononro, ONTARIO, CANADA.

HEATER.

Specification of Letters Patent.

Patented May 22, 1917.

Application filed May 19, 1916. Serial No. 98,689.

To all whom it may concern:

Be it known that I, HARRY S. Door), of the city of Toronto, in the county of York, Province of Ontario, Canada, a subject of the King of Great Britain, have invented certain new and useful Improvements in Heaters, of which the following is a specification.

This invention relates to heaters particularly adapted for the heating of a circulating fiuid'such as air or water or for the generation of steam, and'my object is to devise a heater for thispurpose in which a gaseous fuel can be economically used.

I attain my object by means of the construction hereinafter described and illustrated in the accompanying drawings in which Figure 1 is a vertical section of a heater constructed in acordance with my invention;

Fig. 2 a cross section of the same on the line ab in Fig. 1; and

Fig. 8 a detail showing the lower end of the pipe for admitting air for the pilot light, and a front view of the door ofthe lateral extension of the combustion chamber.

In the drawings like numerals of reference indicate corresponding parts in the different figures.

The device, as usual in heaters of this kind, employs a combustion chamber and radiating system, which, when a heating fluid is to be circulated, is supported by a casing. The casing in the present construction is preferably formed in three sections 1, 2 and 3, the sections being provided with flanges 4 by means of which they may be secured together by bolts as shown. The upper section is provided with an outlet 5 and the lower section with an inlet 6.-

A return pipe 7 is shown connected with the inlet 6 and in this return pipe is shown a thermostat 8. This may be of any desired construction and forms no essential feature of my invention.

The middle section of the casing carries the combustion chamber 9. This combustion chamber is preferably cast integral with the walls of the casing and is provided with the lateral extension 10 which opens through the side of the casing.- This lateral extension provides means of access to the burner 11, which is located at the lower end of the combustion chamber. The outer end of the extension 10 is closed by means of a door 12, the fastenings for which are hereinafter described. It will benoted that the combustion' chamber drops a little below the level of the under side of the lateral extension to form a siunp for the collectionof water of condensation.

The section 2 is also preferably formed with an integral-passageway 13 for the supply of a combustible mixture to the burner, this passageway openingthrough the side of the section as shown so that a supply pipe 14: for the combustible mixture may be screwed therein. The supply pipe for the pilot light used for the burner is also preferably led through this passage.

As a convenient construction, the passage 13 is turned upwardly at right angles below the combustion chamber and the burner 11 is secured thereto. In the under side of the horizontal portion vof the. passage 13'below the vertical portion I form an opening which is closed by the screw plug 15. This plug has a right angled passage formed therein, the vertical part of which has the pilot burner 16 secured therein, while the horizontal portion of the passage is adapted for the reception of the end. of the pilot burner supply pipe 17. This pipe may be screwed in after the plug has been screwed up into position as shown.

' The supply pipe 14 for the'combustible mixture has a gas and air mixing valve located therein, which may be. of any ordinary construction and provided with any ordinary controls.

The upper part of the, casing, while it may be a unitary casting, is preferably formed of a head 19 and a cylindrical wall 21. The head and wall are secured to the outer flange 4 of the middle section 2 by straining bolts 22. Grooves for the reception of the edges of the wall 4: are formed in the head and the flange, and being properly packed, water and steam tight connections are readily formed.

The lower section 3 of the casing is preferably provided with integral lugs 23 to which are secured the standards 24, the lower ends of which are provided withshoes 25 having a ball and socket connection with the'lower ends of the standards so that a good bearing may be obtained despite irregularities in the floor surface.

The radiating or heat transferring system within the casing comprises an upward extension 26 having a tight joint with the upper edges of the combustion chamber 9 and preferably formed integral with an expansion chamber or header 27, the lower header 28 and fire tubes 29 connecting the expansion chamber and the lower header. The expansion chamber 27, it will be noted, is of considerably greater cross sectional area than the combustion chamber and its extension. To the lower header is connected the exhaust flue 30, which extends through the lower part 3 of the casing, preferably concentric with the vertical axis of the heater. The opening in the end of the casing through which the exhaust flue passes is made water and steam tight by a suitable stufiing box 31. The object of this arrangement is to prevent any strain on the radiating system which would result in leakage. The radiating system is subjected at times to sudden changes of temperature, which would cause its expansion or contraction more rapidly than the expansion and contraction of the casing, and as with the construction shown the radiating system is secured to the casing at its combustion chamber end and is otherwise free, its expansion and contraction is quite independent of the expansion and contraction of the casing.

While the fire tubes may be connected with the headers in any suitable manner, I prefer to have their ends fitted into the adj acent surfaces of the headers with tapered ground joints. Through the fire tubes I pass the tubes 32 adapted for the passage of the fluid to be heated. One end of each tube 32 is provided with a head adapted to engage the outer surface of one of the headers and provided at the other end with threads whereby it may be screwed into the outer wall of the other header. These tubes therefore serve as straining bolts to maintain tight joints between the ends of the tubes 29 and the headers. The exhaust flue connects by means of the pipe 33 with an air pump 34. When the device is in operation the pump is run to suck the burnt gases from the combustion chamber and radiating system of the heater. Very intense combustion then takes place in the combustion chamber of the mixture of air and gas supplied to the burner, and very rapid expansion of the products of combustion at once takes place, resulting in a slight pressure in the combustion chamber. Owing to the greater cross sectional area of the ex pansion chamber, these gases immediately expand and the pressure in the expansion chamber will be substantially that in the exhaust flue.

Owing to the suction, combustion takes place not only in the combustion chamber, but also in the expansion chamber 27 where the greatest transfer of heat to the fluid to be heated will take place, the greatest difference existing here between the temperature of the fluid to be heated and the heat transferring surface.

The fire tubes are comparatively long and compensation is thus obtained for their small cross sectional area as compared with that of the expansion chamber. By the time the products of combustion reach the exhaust flue outside the casing, they have been cooled substantially to the temperature of the fluid entering the casing from the return pipe.

In burning gas, water vapor is one of the products of combustion and provision must be made for its removal from the internal heat radiating system of the heater. For this purpose I provide the trapped pipe 35 leading from the sump of the combustion chamber to the interior of the header 28. It will be noted that the upper end of this pipe is slightly above the floor of the sump to avoid having particles of scale and the like pass down to the header.

The exhaust flue 30 communicates with a condensation chamber 36, which is provided with a trapped outlet 37 for the escape of water of condensation. The pipe 33 leading to the fan 34 connects with the upper part of the condensation chamber 36 as shown. As the fluid returning to the casing through the return pipe 7 will seldom have a temperature of much less than 150 degrees Fahrenheit, the exhaust gases will have at least the same temperature. Owing to my use of the pump 34 I am enabled to circulate these exhaust gases through a radiating coil 38 from which the remaining heat units are readily extracted and employed for heating or ventilating purposes.

Reference is hereinbefore made to the door 12. While this may be arranged in any convenient manner whereby it may be given an air tight closure and yet be readily removable, I prefer the construction shown in Fig. 3. The door is closely fitted to a flat face on the casing and is provided with the bearing 39 pivoted centrally thereof. In this bearing is j ournaled the locking bar 40, the ends of which are eccentric to the central journal. One end of this bar is provided with the lever handle 41. Hooked lugs 12 are formed on the middle section 2 of the casing beneath which the ends of the locking bar are readily engaged by turning the bearing 39, and then by rocking the lever 41 the eccentric ends are jammed against the hooks to force the door tightly against its seat.

When the heater is running and the burner alight, all the air required for the combustion of the gas is supplied through the mixing valve 18. When the burner is out, the pump 34 must be stopped and no air supply is then available to maintain the pilot burner 16 alight. Provision for the iii) admission of a suflicient quantity of air for the pilot burner must therefore be made. For this purpose air is preferably admitted to the combustion chamber and also to the expansion chamber 27. This may be done by manually opening certain air inlets, but it is preferable to arrange these to open automatically. I therefore provide in the door 12 an opening 43, the face of the door about the opening being inclined in an inward and downward direction. Over this is hung a thin valve flap 44, which, when there is no suction in the combustion chamber, hangs straight down so that air may pass to supply the pilot light. As soon as suction exists the light flap is drawn inwardly to close the opening.

A similar opening 45 is formedthrough the section 2 of the casing. With this opening communicates the lower end of the pipe 46, the other end of which communicates with the interior of the expansion chamber 27. The opening 45 is similarly arranged to the opening 43 and is provided with the hinged valve flap 47.. By carrying the pipe 46 down and through the section 2 of the casing instead of up through the upper part of the casing, I materially facilitatethetaking apart of the apparatus for cleaning or repairs.

It will be seen that when it is desired to take out the radiating systemfor repairs that the lower section with all its connections may remain in place while the two upper sections are separately removed and the internal radiating system drawn out for repairs. A mica-covered peep hole 48 is preferably provided in the door 12.

What I claim as my invention is:

1. In a heater the combination of a tubular closed combustion chamber; a gas burner located adjacent one end of the chamber; a closed expansion chamber or header of greater cross sectional area than the combustion chamber and into which the other end of the combustion chamber opens; means for supplying a combustible mixture to the burner; a plurality of fire tubes connected to the expansion chamber and substantially paralleling the combustion chamber; a header to which said tubes are connected; an exhaust flue connected to said header; and an air pump connected with the exhaust flue.

2. In a heater the combination of a tubular closed combustion chamber; a gas burner located adjacent one end of the chamber; a closed expansion chamber or header of greater cross sectional area than the combustion chamber and into which the other end of the combustion chamber opens; means for supplying a combustible mixture to the burner; a plurality of fire tubes connected to the expansion chamber and. substantially paralleling the combustion chamber; aheader to whichsaid tubes are connected; tubes for the passage of a fluid to be heated extending through the fire tubes to the outer surfaces of the expansion chamber and header; an exhaust flue connected to said header; and an air pump connected with the exhaust flue.

3. In a heater the combination of a tubular closed combustion chamber; a gas burner located adjacent one end of the chamber; a closed expansion chamber or header of greater cross sectional area than the combustion chamber and into which the other end of the combustion chamber opens; means for supplying a combustible mixture to the burner; a plurality of fire tubes connected to the expansion chamber and substantially paralleling the combustion chamber; a header to which said tubes are connected; an exhaust flue connected to said header; a trapped pipe for water of condensation leading from the bottom of the combustion chamber to the interior of said header; and an air pump connected with the exhaust flue.

4. In a heater the combination of a tubu lar closed combustion chamber; a gas burner located adjacent one end of the chamber; a closed expansion chamber or header of greater cross sectional area than the combustion chamber and into which the other end of the combustion chamber opens; means for supplying a combustible mixture to the burner; a plurality of fire tubes connected to the expansion chamber and substantially paralleling the combustion chamber; a header to which said tubes are con nected; an exhaust flue connected to said header; a condensation chamber with which said exhaust flue connects; a trapped liquid outlet therefrom; and an air pump connected with the exhaust flue.

5. In a heater the combination of a tubular closed combustion chamber; a gas burner located adjacent one end of the chamber; a closed expansion chamber or header of greater cross sectional area than the combustion chamber and'into which the other end of the combustion chamber opens; means for supplying a combustible mixture 7 to the burner; a plurality of fire tubes connected to the expansion chamber and substantially paralleling the combustion chamber; a header to which said tubes are connected; an exhaust flue connected to said header; a trapped pipe for water of condensation leading from the bottom of the combustion chamber to the interior of said header; a condensation chamber with which said exhaust flue connects; a trapped liquid outlet therefrom; and an air pump connected with the exhaust flue.

6. In a heater for fluids the combination of a substantially vertical outer casing, provided with a fluid inlet and a fluid outlet; a closed combustion chamber located in said 'to the other about the chamber; and an exhaust flue from the lower header leading through the lower part of the casing.

7. In a heater for fluids the combination of a substantially vertical outer casing, provided with a fluid inlet and a fluid outlet; a closed combustion chamber located in said casing intermediate of its ends; a lateral extension of the combustion chamber near its lower end extending through the casing; a door adapted to effect a substantially airtight closure of the outer end of said exten sion; a burner located in the combustion chamber adjacent its lower end; means for supplying a combustible mixture to the burner; a header into which the upper end of the combustion chamber opens; a header located below the combustion chamber; means for the passage of the products of combustion extending from the one header to the other about the burner; a trapped pipe for water of condensation leading from the bottom of the combustion chamber to the interior of said header; and an exhaust flue from the lower header leading through the lower part of the casing.

8. In a heater for fluids the combination of a substantially vertical outer casing, provided with a fluid inlet and a fluid outlet; a closed combustion chamber located in said casing intermediate of its ends; a lateral extension of the combustion chamber near its lower end extending through the casing; a. door adapted to effect a substantially airtight closure of the outer end of said extension; a burner located in the combustion chamber adjacent its lower end; means for supplying a combustible mixture to the burner; a header with which the upper end of the combustion chamber opens; a header located below the combustion chamber; means for the passage of the products of combustion extending from the one header to the other about the burner; a trapped pipe for water of condensation leading from the bottom of the combustion chamber to the interior of said header; an exhaust flue from the lower header leading through the lower part of the casing; a condensation chamber with which said exhaust flue connects; and a trapped liquid outlet therefrom.

9. In a heater for fluids the combination of a casing formed in three sections divided horizontally and detachably secured together, the upper section being provided with a fluid outlet and the lower with a fluid inlet the middle section being an integral casting shaped to form a central combustion chamber a lateral extension thereof opening through the side of the casing, and a gas supply conduit extending from the combustion chamber to the exterior of the casing in combination with a radiating flue system connected with the combustion chamber; and an exhaust flue connected therewith extending through the casing.

10. In a heater for fluids the combination of a casing formed in three sections divided horizontally and detachably secured together, the upper section being provided with an outlet and the lower with an inlet, the middle section being an integral casting shaped to form a central combustion chamber a lateral extension thereof opening through the side of the casing, and a gas supply conduit extending from the combustion chamber to the exterior of the casing in combination with a radiating flue system connected with the combustion chamber; an exhaust flue connected therewith extending through the bottom of the lower part of the casing; and a stufling box forming a tight 9 joint where the flue passes through the casmg.

11. In a heater for fluids the combination of a casing formed in three sections divided horizontally and detachably secured together, the upper section being provided with an outlet and the lower with an inlet, the middle section being an integral casting shaped to form a central combustion chamber a lateral extension thereof opening 5 through the side of the casing, and a gas supply conduit extending from the combus tion chamber to the exterior of the casing in combination with a radiating flue system connected with the combustion chamber 119 comprising an upward extension of the combustion chamber, an expansion chamber into which the upper end of said extension opens,

a header located in the lower part of the casing, and fire tubes detachably connected 5 to said expansion chamber and header; and

an exhaust flue connected to the header and extending through the casing.

12. In a heater for fluids the combination of a casing provided with a fluid inlet and 120 a' fluid outlet; a combustion chamber located in and supported by said casing intermediate of its ends; a header into which the upper end of the combustion chamber opens;

a header located below the combustion chamber; means for the passage of the products of combustion extending from one header to the other about the combustion chamber; an exhaust flue leading from the lower header through the lower part of the casing and slidable therethrough; and means for packing the opening through which said flue passes.

13. In a heater for fluids the combination of a casing provided with a fluid inlet and a fluid outlet and divided horizontally; a combustion chamber integral with the casing below the line of division; a header within the upper section of the casing into which the upper end of the combustion chamber opens separated from and secured to the combustion chamber; and an air pipe opening into the header and also communicating with an opening in the casing below the line of division.

14:. In a heater for fluids the combination of a casing provided with a fluid inlet and a fluid outlet and divided horizontally; a combustion chamber integral with the part of the casing immediately below the line of division and having an integral lateral extension opening through the side of the easing; a radiating flue system connected with the combustion chamber comprising a separate upward extension of the combustion chamber, an expansion chamber into which the upper end of the said extension opens, a header located in the lower part of the easing and fire tubes detachably connected to said expansion chamber and header; and an exhaust flue connected with said radiating system extending through the lower part of the casing.

Signed at Toronto, Ont, this 19th day of April, A. D. 1916.

' HARRY S. DODD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

